Tri-Amp & Time aligned K Horn

[Chris A]

Tells me all the cash spent in tweaks is best spent on music. :-)

Actually, this says that the Khorn has driver delay mismatches that really do need to be corrected.

P.S. What is the year count on this design?

I'm not sure if you are asking about the Khorn design, the article publish date, or the results of the test by Rigma, et al. The article was published in November 1986 and is probably the most famous review written on the Khorn. Richard Heyser was a pioneer in the use of waterfall FFT diagrams and other testing techniques. His untimely death was a great loss to the profession.

Chris

[jcmusic]

After reading through this thread I am wondering how much of a difference room size makes??? For instance in a room 12X14X8 vs a 15X22X9 room how much difference in time dely is according to room size???

Jay

[o0O Bill O0o]

Tells me all the cash spent in tweaks is best spent on music. :-)

Actually, this says that the Khorn has driver delay mismatches that really do need to be corrected.

P.S. What is the year count on this design?

I'm not sure if you are asking about the Khorn design, the article publish date, or the results of the test by Rigma, et al. The article was published in November 1986 and is probably the most famous review written on the Khorn. Richard Heyser was a pioneer in the use of waterfall FFT diagrams and other testing techniques. His untimely death was a great loss to the profession.

Chris

Point 1 , I think you're right. Is the juice worth the squeeze? ~$$$$ in modifications, yeah I'm sticking with the stock design. This translates well to cars.

Point 2 , I was referring to the original klipschorn design.

Also,Canyonman, room size.. Someting with the golden ratio. 1:1.618 with the smallest dimension > ~10''

[Chris A]

Point 1 , I think you're right. Is the juice worth the squeeze? ~$$$$ in modifications, yeah I'm sticking with the stock design.

If I had a car habit, I'd make quite sure that I didn't listen to time-aligned Khorns if I were going to continue to place my discretionary budget in cars...

Chris []

[artto]

The Heyster review of the K-Horn in Audio reported that at his mike position about 1 meter away from the front of the speaker:

Regards,

Gil

WOW. Gil, you're usually (almost always, except this one time) right on the mark. However, I'm going to take this extremely rare opportunity to make a correction (besides the typo of Richard's last name, LOL).

From Richard Heyser's Audio magazine review originally published November, 1986 and reprinted in The Best of Audio Volume IV November, 1989:

"The Klipschorn is also intended to be listened to at ranges greater than 3 meters. The substantial size of this speaker and it's geometry require that measurements be performed at such distance, and I have choosen 3 1/2 meters since this the distance at which I listened to these units."

Going on he says:

"The (measurement) plot is corrected for an equivalent distance of one meter on axis relative to the front of the enclosure, although the actual measuring distance is 3 1/2 meters".

For those interested this article is included in the set of Klipsch documents I provided here years ago. It's posted in several locations around the Forum as "The Paper" in PDF format which Forum member Justin16 (?) so kindly scanned.

(please don't even think of selling these on places like Ebay ~ thanks).

BTW ~ I have a really nice Shanling SCD-T200 tube Super Audio player for sale. It's been fully serviced with new laser and servo, spindle height adjustment, external & internal connections cleaned, etc. []

[Guest " "]

When we talk about Khorn driver delay times, I wonder how important it is to consider the effect the subject referenced khorns crossover capacitor slew rate had on the delay times indicated. Capacitor slew rate adds to the delay time. If you are going true active with no driver protection (no passive capacitors), will the delay time of your installation be different than the the subject khorns. If the subject khorns had Paper and oil caps, and you have no caps, or metal film caps, differences? If the subject khorns had AA and you have AL-4, differences? Or, was the indicated delay times a calculation based solely on the physical distance between drivers and did not even consider the contribution capacitor slew rates have on the delay time?

[Don Richard]

That's why it is good to do an acoustic alignment at the listening position. If TEF or another TDS type measurement system isn't available the Altec method can be used. Basically, you run a sine tone at the crossover frequency, invert the polarity of one driver, and tune the delay time until maximum null is shown on a SPL meter. Don't forget to restore proper polarity after the delay is set for that crossover point. If you are using blocking caps this compensates for any phase shift they cause.

[Chris A]

Interesting that the audiophile community doesn't talk about using this simple test to check speaker performance...

However, it doesn't really correct for delays more than 360 degrees out, right? It would take some sort of impulse test (like REW) to see it.

Chris

[Don Richard]

If you use the physical offset between drivers at the woofer to mid crossover as a starting point you won't get 360 out. It is more difficult at 6kHz, but you will probably want to replace the K-77 anyhow, and then you can go to a lower crossover point.

[jcmusic]

Let me ask again, how relivant is time delay in a smallish room if the listening position is lets say 12 feet away???

Jay

[PrestonTom]

Let me ask again, how relivant is time delay in a smallish room if the listening position is lets say 12 feet away???

Jay

The issue of time delay is important because the phase of the two drivers in the crossover region will not be fixed and you will get and uneven frequency response (the drivers' outputs will add in-and-out of phase) and you will also get some lobing.

If the crossover filters are steep, then there is less spectral overlap and the problem is minimized. If the delay difference is huge, then the delay (technically, the group delay) will be audible. In a room with reflections, the audibility is minimized, and you need an even larger delay for it to be audible. There is not a large literature on this topic and there are some caveats so I will not bother giving exact numbers on the threshold of audibility for these delays. With the Klipschorn the problem is mostly confined to the first issue (the crossover problem)

So in answer to your question, the problem is not directly a function of the room size.

-Tom

[jcmusic]

Let me ask again, how relivant is time delay in a smallish room if the listening position is lets say 12 feet away???

Jay

The issue of time delay is important because the phase of the two drivers in the crossover region will not be fixed and you will get lobing.

If the crossover filters are steep, then there is less spectral overlap and the problem is minimized. If the delay difference is huge, then the delay (technically, the group delay) will be audible. In a room with reflections, the audibility is minimized, and you need an even larger delay for it to be audible. There is not a large literature on this topic and there are some caveats so I will not bother given exact numbers on the threshold of audibility for these delays. With the Klipschorn the problem is mostly confined to the first issue (the crossover problem)

So in answer to your question, the problem is not directly a function of the room size.

-Tom

Hey Tom, thanks for repying and for the explanation. OK the problem is not directly a function of the room size, agreed can the room size make the problem worst? Or less noticeable in a smaller room?

Jay

[JL Sargent]

I have done tests here with time alignment (physical and electronic) on drivers from Altec and Klipsch. I took speaker components and physically aligned the voice coils and listened. I then misaligned these same components and listened. I simply found that time alignment was not noticable to me. Your results may vary.This of course makes perfect sense since Klipsch speakers aren't shipped with time aligned drivers.

[djk]

" I simply found that time alignment was not noticable to me. "

The stock crossovers are not the best for time-aligning.

You will have trouble getting things to sound right with 12dB or 18dB crossovers, period. 12dB can sum flat if a LR type, but must be hooked up out-of-phase. 12dB in-phase will have an infinite hole at the crossover point. 18dB will sum flat in-phase or out-of-phase. None of these are an optimal solution.

[DrWho]

Let me ask again, how relivant is time delay in a smallish room if the listening position is lets say 12 feet away???

Jay

The issue of time delay is important because the phase of the two drivers in the crossover region will not be fixed and you will get lobing.

If the crossover filters are steep, then there is less spectral overlap and the problem is minimized. If the delay difference is huge, then the delay (technically, the group delay) will be audible. In a room with reflections, the audibility is minimized, and you need an even larger delay for it to be audible. There is not a large literature on this topic and there are some caveats so I will not bother giving exact numbers on the threshold of audibility for these delays. With the Klipschorn the problem is mostly confined to the first issue (the crossover problem)

So in answer to your question, the problem is not directly a function of the room size.

-Tom

Agreed, but I wanted to add that I don't think polar lobing is the only issue at play...

Audibility of two discrete events is certainly not a concern at these magnitudes of delay, but the relative timing (phase) of multiple frequencies is part of what determines the timbre of an instrument. I have found that one of the most audible artifacts of time-misalignment shows up in the timbre of a good snare drum. Mis-aligned will sound more soft and mushy, whereas perfect alignment will sound more tight and crisp....with the tight and crisp sounding much more like the real thing. One of these days I'll get around to writing a Matlab script to visually depict the behavior (though the visual representation is going to look much more dramatic than the actual audible impact).

Sadly, time-alignment can only fix these phase errors along one-dimension....so some of the off-axis behavior will still have these artifacts (unless your tweeter acoustic center shifts back in the off-axis...). I believe this is partially why using less transducers (say 2-way vs 3-way) can be beneficial towards acheiving a more cohesive sound. However, I think distortion and power response relationships have a bigger play in that regard, but just thought I'd throw it out there anyway.

[Coytee]

I believe this is partially why using less transducers (say 2-way vs 3-way) can be beneficial towards acheiving a more cohesive sound

Given my lack of technical prowess, I gotta put my vote here with Who. I was attributing the cohesive sound of the Jubilee's to their being signal aligned. It was Ben who wacked me over the head and said it was because they were 2-way. Furthermore, he suggested I dinker around with the delay to see if I could tell a difference.

Though I could certainly add enough delay to create distinct echos once I got back in the ballpark for echo to go away (still not aligned as per Roy's numbers) they still had that cohesiveness that I noticed.

I'd say the lions share of improvement comes from dropping a crossover point and then you get incremental gains by the signal alignment.

I'll admit it kind of has me intrigued with those single driver speakers... (not enough to get rid of anything)

[o0O Bill O0o]

I believe this is partially why using less transducers (say 2-way vs 3-way) can be beneficial towards acheiving a more cohesive sound

Given my lack of technical prowess, I gotta put my vote here with Who. I was attributing the cohesive sound of the Jubilee's to their being signal aligned. It was Ben who wacked me over the head and said it was because they were 2-way. Furthermore, he suggested I dinker around with the delay to see if I could tell a difference.

Though I could certainly add enough delay to create distinct echos once I got back in the ballpark for echo to go away (still not aligned as per Roy's numbers) they still had that cohesiveness that I noticed.

I'd say the lions share of improvement comes from dropping a crossover point and then you get incremental gains by the signal alignment.

I'll admit it kind of has me intrigued with those single driver speakers... (not enough to get rid of anything)

Okay has anyone figured the cost of this mondifaction?

I think that is the biggest limiting factor. I say that none of us has the staff and test capability that Klipsch or any good speaker company has. In the spirit of modification, sure it's cool. But falls short on true deliverables and really is all in the mind of the owner.

Spend money on music or even another set of speakers *cough single driver/ coaxial* that are true time aligned designs.